Treating disease with microbes: Bugs in the system, Bacterial medicine is starting to emerge

ONE of the crucial transitions of modern health care was from herbal to chemical medicine. Doctors had known for millennia that willow bark and poppy sap relieve pain. But it was not until the late 19th century, when Felix Hoffman synthesised versions of their active ingredients, namely acetylsalicylic acid and diamorphine (or aspirin and heroin, as they are more commonly known), that proper pharmaceutical science got going.